John Perkins

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Questions related from John Perkins

How does the sequence of an old age tetraploid formed by the triploid bridge different from one formed by duplication?

When one examines the sequences of a tetraploid population of plants can one tell whether the pathway from diploid to tetraploid included the use of the triploid bridge? In others words can you...

26 February 2020 589 0 View

For flowering plants, is an autotriploid or an allotriploid more likely to be fertile?

In general are triploids more likely to be seed fertile if the the parents are closely related or distance relatives?

27 July 2016 488 2 View

For flowering plant, how much evidence is there for polyploid introgression downward into the original diploid populations?

In the genus Rhododendron, hand crosses demonstrate that both triploid and tetraploid seed parents can produce diploid offspring. For flowering plants, how much evidence is there for polyploid...

09 June 2016 1,275 2 View

When crossing a given diploid X given tetraploid, what causes some of offspring to be fertile while most are sterile?

For flowering plants when crossing a given diploid X given tetraploid of closely related species, what causes some of triploid offspring to be very seed fertile while most are sterile? We are...

03 June 2016 4,009 7 View

Focusing on flowering plants, are there reasonable explanations why pentaploids would be more fertile than triploids?

For the genus Rhododendron, triploids are sometimes fertile but pentaploids appear to be often fertile. Once Rhododendron seedlings gets above the triploid level, aneuploids not near euploid...

27 December 2015 10,233 22 View

Does a .1 increment in flow cytometry scores for closely related species from 1.8 to 3.8 indicate an increase in the number or length of chromosomes?

Does a .1 increment in flow cytometry scores for closely related species from 1.8 to 3.8 normally indicate an increase in the number or length of chromosomes where 1.2 to 1.4 normally indicates...

29 November 2014 3,231 3 View

When crossing plants of differing ploidy level, what can cause a parent to contribute less than half of its chromosomes to its offpspring?

When crossing polyploid Rhododendrons we have noticed some offspring have a 2C value that is less than the C value of the seed parent + C Value of pollen parent. This can be true even when the...

22 November 2014 6,602 9 View

For flowering plants, can a sport of a triploid become diploid or tetraploid?

Using flow cytometry, documented sports of triploid Rhododendrons have tested as diploid, triploid, and tetraploid. The sports were documented as propagated from cuttings. Does anyone know other...

01 January 1970 4,971 2 View

How are chromosomes lost during mitosis?

The research paper "In Characteristics of a Dwarf Octoploid Mutation Arising from a Nonaploid Persimmon Cultivar" documents an occurrence of the lose of chromosomes during mitosis. How does sure...

01 January 1970 1,500 0 View